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diff --git a/source/blender/blenkernel/BKE_lib_principle_properties.h b/source/blender/blenkernel/BKE_lib_principle_properties.h
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+/* SPDX-License-Identifier: GPL-2.0-or-later
+ * Copyright 2022 Blender Foundation. All rights reserved. */
+
+#pragma once
+
+/** \file
+ * \ingroup bke
+ *
+ * API to manage principle properties in data-blocks.
+ *
+ * Principle properties are properties that are defined as the ones most user will need to
+ * edit when using this data-block.
+ *
+ * They current main usage in is library overrides.
+ *
+ * \note `BKE_lib_` files are for operations over data-blocks themselves, although they might
+ * alter Main as well (when creating/renaming/deleting an ID e.g.).
+ *
+ * \section Function Names
+ *
+ *  - `BKE_lib_principleprop_` should be used for function affecting a single ID.
+ *  - `BKE_lib_principleprop_main_` should be used for function affecting the whole collection
+ *    of IDs in a given Main data-base.
+ */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct ID;
+struct IDPrincipleProperties;
+struct IDPrincipleProperty;
+struct PointerRNA;
+struct PropertyRNA;
+struct ReportList;
+
+/**
+ * Initialize empty list of principle properties for \a id.
+ */
+struct IDPrincipleProperties *BKE_lib_principleprop_init(struct ID *id);
+#if 0
+/**
+ * Shallow or deep copy of a whole princple properties from \a src_id to \a dst_id.
+ */
+void BKE_lib_principleprop_copy(struct ID *dst_id, const struct ID *src_id, bool do_full_copy);
+#endif
+/**
+ * Clear any principle properties data from given \a override.
+ */
+void BKE_lib_principleprop_clear(struct IDPrincipleProperties *principle_props, bool do_id_user);
+/**
+ * Free given \a principle_props.
+ */
+void BKE_lib_principleprop_free(struct IDPrincipleProperties **principle_props, bool do_id_user);
+
+/**
+ * Find principle property from given RNA path, if it exists.
+ */
+struct IDPrincipleProperty *BKE_lib_principleprop_find(
+    struct IDPrincipleProperties *principle_props, const char *rna_path);
+/**
+ * Find principle property from given RNA path, or create it if it does not exist.
+ */
+struct IDPrincipleProperty *BKE_lib_principleprop_get(
+    struct IDPrincipleProperties *principle_props, const char *rna_path, bool *r_created);
+/**
+ * Remove and free given \a principle_prop from given ID \a principle_props.
+ */
+void BKE_lib_principleprop_delete(struct IDPrincipleProperties *principle_props,
+                                  struct IDPrincipleProperty *principle_prop);
+/**
+ * Get the RNA-property matching the \a principle_prop principle property. Used for UI to query
+ * additional data about the principle property (e.g. UI name).
+ *
+ * \param idpoin: RNA Pointer of the ID.
+ * \param principle_prop: The principle property to find the matching RNA property for.
+ */
+bool BKE_lib_principleprop_rna_property_find(struct PointerRNA *idpoin,
+                                             const struct IDPrincipleProperty *principle_prop,
+                                             struct PointerRNA *r_principle_poin,
+                                             struct PropertyRNA **r_principle_prop);
+
+#ifdef __cplusplus
+}
+#endif